Brake applying system



Aug. 1', 1944. G KEITH ETAL 2,354,687

BRAKE APPLYING SYSTEM Filed April 28, 1942 Patented Aug. 1, 1944 um'rizoThis invention relates to automatic brake 'ap'-- plying devices forautomotive vehicles. I

More specifically, the invention providesmeans for automaticallyapplying or setting the brakes of an automotive truck or other vehicleupon the driver thereof becoming incapacitated.

The invention is of peculiar utilityandhas par-1 ticular application tomilitary vehicles, especially such as are used under actual combatconditions; It hasheretofore been recognized that whenever for anyreason the driverof any type of automo-- tive vehicle becomesincapacitated, it is desirable. that the vehicle be brought promptly torest. Obe viously, the need for automatic stopping means is'greatest inthe case of military vehicles operated under combat conditions, sinceunder such, circumstances the drivers of such vehicles-- are subjectedto'the hazards of gunfire in addition to what may be considered ordinaryand :normal factors tendingto distract or incapacitate any driver:

Attempts have been made heretoforeto provide means in automotivevehicles which-will-re= quire thedriver to make a deliberate and con-.scious effort to'maintain the which will be automatically operative toapply; thebrakes'upon' the cessation ofsuch efiort, How-.

ever, the best of such prior art systems have. proved to be impracticaland inefiectivefor various reasons. An important object of ent inventionis to introduce improvements to kept systems of this general type out ofwidespread use. r

A related object of the invention is to simplifythe physical structureand to embody it in a form which is inexpensive to manufacture andeasytoapply to existing vehicles.

A further object is to provide an actuating means which willautomatically set the brakes without fail upon the driversbecomingincapacitated, eventhough the driver lose consciousnessand slump overthesteering wheel.

A further important object provide .an

electrically controlled mechanism for accomplish-- ing the foregoingpurposes and to incorporatein such mechanism means for opening theoperating, circuit after a predetermined period of time, so

that unnecessary drain on the battery or other current source isavoided.

A still further object is to incorporatein a sys tem of the classdescribed'means for applying in brakes released and:

the pres:

eliminate the defects and disadvantages that have from :the load borneby the emergency operating system those actuatin'g'or controlling parts'which' are'peculiar-tothe "normally used systemi More specifically; thepresent system .=is electrir'ially' 0p f .erated and employs the'us'ual.standard"brake shoes and drums, but these 'inst'rumentalitiesare operated under emergency conditions without moving the conventional'sprin'g-operatedi pedal and its-associated linkage. 3 1

An additionalobject is toincorporate a sys-' tem go-f this general classa? physical" construetion which will be foolproof and unfailing inToper-' ation and which can-not be circumvented by'a driver of thevehicle on'which it i's'zprovide'd',

Further objects-andiadvantages of the'system will become 'apparentwasthe followingidescri'p-* tion of a preferred form of embodiment isreadin connection with the appended'drawing; F I

Inthe drawing, T

Figure 1 shows, generallyxscliematically, in plan view the runninggear-40f a conventional typeof automotive vehicle having a fiuid brakingsystem, ;With" one embodiment of l the; present inven-*tion=incorporatedthereimw n 1 Fig. 2. shows in l'ongitudinal verticalsection'cer-' tain' parts of the" new system, including a. brake pedal,amaster cylinder; and a"solenoiddevice";

Fig; 3 shows in axial-.- section a portio'n o'f a' steering column with'certainrofthe con'trlol :partsofthetpresent inventioni mounted'therein' 1:

-It;is to be ,understoodat the'outsetthatithe invention is of wideapplicatidnand may-be em-' bodied in forms. and physicalstructureidifierent from those selected for" illustration; :The drawingis of. generally. diagrammatic "type. and "does not purport todepict-all the structural details in which the system is incorporated;"IThOSB. details may be 'Variedeonsiderably?within. the broad principlesof --the.-invention as defined .by the ap pendedclaims. I

In the drawing, Fig. '1 illustratesa;conventional running gear includingaframe; 5; wheels '6,-'brake housings} brake fluid conduit branchest,master bralge linesvfl; a master cylinder; NL and apedal l toperativelyconnected by aired 12 to the-piston l3 (Fig.2) ofithemastercylinder.*The arran e-1 ment maybe a power brake system includinga reservoirl 4,or it maybea simplemanualsystem.

Ineither case,.,the housin s I- enclose suitable brake shoes cooperating.with -brake..1drums, ap-.

plicable by ;.pressure,inw the branch lines andretractablaby-springdevicesonthe like. Allr-the foregoing is conventional and Well -knownandE neednot. described with ,further particularity.

tion 20 and a lower portion 2|, which are splined; together by theinterfitting of integral keys 22 I and keyways 23, as shown in Fig. 3.The lowerportion 2| is relatively fixed and operates the customarysteering gear.

The upper portion 20" is free to move axially with respect to the lowerportion, while the two portions are constrained Any other expedientpermiti to rotate together. ting axial lifting and dropping of the upperportion while preventing relative rotation of the upper and lowerportions may be adopted.

The force of gravity normally keeps theupper portion in itsilowermostposition, belowfthat illustrated in 'Fig. j3,*but the arrangement issuch thatto operate the ;vehicle the driver must pull upwardly on thesteering wheel to maintain the upper portion 20 in its uppermostposition, higher than that illustrated in Fig. 3. I The arrange-'- mentis such that if the column is allowed to drop, thebrakeszwillbe'automatically applied for a predetermined interval 01'time, following which they'will be released inorder to preventwaste ofthe applying p'owe'r,i which in the present case is electrical energy;"This -is accomplished by the novel. control means incorporated in aspecial housing 26 provided on the steering column? which will now bedescribed. 4 r

The housing or casing 26 is made in the form of two telescoping halves,each annular in'plan, the upperhalf 21*being sleeved around'and fasteneditofthe" upper portion 20 of thesteering column, and the"lower halfbeing sleeved around and fastened to the lower; portion 2| of thecolumn. 'A' brake-controlling switch 29 is provided in'the'casing andcomprises an electrical contact" button '30'mounted in and m n: latedfrom one of the halves, as for example the half 28,'; and a cooperatingswitch finger 3| mounted inandl-insulated from the other half} wireleads 32, :33 being connected to the button' and finger respectively andissuing from the casing through a packed opening. i The switch finger isspecially constructed, com-f prising a resilient 'strip 34 of conductivemetal 5 terminating atits free end portion-in a non-conducting backing35 clamped-at 35' aroundlth'e lower end of a strip of highresistancem'etal '31 whose upper en'd'is in electrical contact with thestrip 34 and is clamped thereto by a rivet or the like 38 which passesthrough the nonconductingbacking 35' and a front facing button 39 0|.nonconducting'material.-' i The leads 32, 33 are extended respectivelyto'a solenoid 40 and toasource of electrical energy. which may betheusual battery 4| of the vehicle,

as shown in Fig. 1'. For the sake of simplicity the battery isshowndirectly connected, but off courseany" suitable coil or the likemay be interposed to modiify the characteristics of the cur rent orvoltage supplied-to the solenoid. The armature ofthe solenoid is a rodor the like 42 extended through a'gland'43 from the piston |3 ofthemastrbrake' cylinder ID; or otherwise rigidlyconnectedtotheoper'ating rod l2 thereof. I

It will be apparent that with the parts in the position shown in Fig. 3a circuit will be completed through the switch 29 to energize thesolenoid and apply the brakes, while the circuit will be open if theupper portion 20 of the steering column is raised to bring the lower endof the nonconducting strip 35 into engagement with the button 30 or ifthe upper portion 20 is dropped to bring the nonconducting button 38into such engagement. Obviously, in order to maintain the brakesunapplied, so that the vehicle can be operated, the steering wheel mustbe kept in its uppermost or its lowermost position.

- It is an object of the invention to require the a operator to keep thesteering wheel in its upper- Imostposition in order to enable thevehicle to be driven, and this is accomplished by cooperation of theignition circuit switch shown at the lefthand side of Fig. 3. Thisswitch includes a metallic button 5| mounted in and insulated from thelower half 'of the casing 26 which isrubbed by a spring finger 52carried by and insulated lowered position the ignition circuit is openby engagement of parts 55 and 5|, while the ignition circuit is closedthrough the switch 50 only when'the steering'wheel is held in uppermostposition so as to bring the parts 54 and 5| of the switch 50 intoengagement. 'In this latter position, it will be remembered, parts 36and 30 of the switch 29 are engaged, so that the brake-' applyingcircuit is open. Thus the vehiclecan be driven only so long as thesteering wheel is held up against the tendency of gravity to lower it,or against the action of some positive lowering means, such as a spring,weight or the like which may be optionally employed for the pur pose.

' It is obvious that as soon as the driver for any reason ceases holdingthe steering wheel up, the brakes will be electrically appliedautomatically and the vehicle motor will be shut o'fi. Assuming that theclutch parts remain engaged, the drag of the dead motor will contributematerially toward bringing the vehicle to a stop. The use of highresistance material for the strip 31, which is desirable but optional,has the advantage causing the amount of the current flowing through theswitch 29 to the solenoid 40 to increase gradually as the steering wheelsettles, so that application of the brakes is not abrupt or sudden butis progressive and gradual. When the wheel has dropped almost to itslowermost position the brakes are most powerfully applied, since thelength of high resistance metal 31 traversed by the current is thenshortest, and immediately thereafter, when the wheel has dropped to itslowermost position, the button 39 engages the button 30 and thebrake-applying circuit opens, in order to avoid unnecessary drain on'thebattery 4| or other source.

It is assumed that the vehicle will have been brought to a complete stopby the time the wheel settles tolowermost position and the brakes become released. To make certain'that the brakeapplying circuitremainsclosedduring a sufficiently longtime it is desirable to provideretarding or time-delay zmeans at some appropriate place in the systemtozprevent too rapid movement of the parts. .i'Aconvenient type of suchmeans is a daslipot, and Fig. 3qsh'ows a form of dashpot incorporated inthe. structure of the casing 26. As there shown, -the'-1halvesiof thecasing make a quite snugjfit with each other and with thesteering-column so that air will be compressed within the casing whenthe halves move together and such movement will be'delayed and retardedwhile the. compressed air leaks out from the casing. If desired, anadjustable air exit port may be provided in; the casing.--. Of coursethe openings through whichthewire leads ,32, 33, 56,51 extend are .well.packed to prevent undesired leakage. Conveniently all these leads willissue through a single gopening; but 1 they are shown separatedinthgdrawing-for the sake of simplicity and clarity of illustration.

The dashpot feature involves a further 7 advantage since it prevents.undesired lowering-oi the steeringwheel-and application of the brakesinresponse to vibration orajolting of the vehicle and the driver. The.diflicultyof maintaining the steering wheel constantly in fulluppermost position while travellingover rough .terrain may sometimes beconsiderable, but itis-minimized by the resistance to.loweriiigafforded'by the dashpot feature. As a further'safegnardagainstaccidental and undesired lowering of. the wheel to an extentthatwoul-dappl'yjthebrakes'it is best to arrange the ,proportionsjoji the vpartsof the switches 29 and 50 insuch .a way that as the wheel moves down.the'switch'lii! will'openbefcre' the switch 29 closes ln ..this. way,should the driver inadvertently'tend 'to allow the. steering wheel tosettle too far down lhe will be warned of that-fact by the momentarycutting off of the ignition current so 'thathe can promptly raise thesteering wheel before. the brakes become applied.

In order to iacilitateiflifting of the steering wheel against thepartialvacuumlthat would otherwise be producedfin'the casing 26, it isconvenient to providea check valve like that shown at 60. It will beunderstood that this valve-opens in response to atmospheric pressurewhen the upper half of the casingisilifted and drops in response togravityimmediately"thereafter, remaining closed when the upp'erhalfsofthecasing is lowered. s q

In order to. relieve the. load which must be moved by the solenoid'iinapplyingdthe brakes it is desirable to provide a loose connection likethat shown at 65 the master brake cylinder piston rod 12. As thereshown, thercd-is divided into the portions 12 and 66 which are connectedby splining H on one of-the-divisions' travelling in a slot orplurality-of slotsformedina sleeve 68 mounted on the otherdivision.-.;'I'his construction enables movementof the division 66 t0the right in 1 2 in; response to downward movement of the pedall},to-engageand move the division i2 just as though the two divisions wereone, while the armature .42 is ,able to pull the piston l3 to the rightwithout having-to. move the division 56, the pedal H, the interposedlinkage and the customary.YQpedal-retractingspring.

A master. control switch, preferabl lock-controlled and diagrammaticallyindicated at 10 in Fig. 1, may be included anywhere inthebrakeapplyingcircuit to render this. circuit inoperative whenever desired.similanswitch (:notshown).

that in. commercial produc-- tion lthe parts will be considerably.simplified.-

For example, it is proposed to unite the switches 29 and. .50 bymounting the lower, fixed -buttons of. these two switches .on a singlesupportiand ;by mounting the upper, movable" fingers thereofutogether.The switches are shown separated and independent in the drawingin orderto make theiriunction and essential structure clearuand' readilyunderstandable.

. It will be obvious that the, several circuits; ene; teringthe casing26. need-not require as many the-:four leads thereto which are shown inthe. drawing for the sake of simplicity and clarity, since some of theelectrical contacts can jbe. grounded and. ground paths :may thus be'substituted for wire connections. In either case,- whether wireconnections or ground paths areused, it is preferable to extend all theleads out. from the casing throughasingle opening, since this willmakeit necessary: to pack one-opening: instead ofatwo'. The wiring isj'ofcourse hasten-.- closed in suitable armored sheathing to prevent damageand tampering. 2 I :1

It .is believed now to be clear thatthe systemcovered by thisapplicationyexplainedhereinabove in one exemplaryor representativeformof embodiment, accomplishes; the objects set out first hereinaboveand incorporates numeroussubstantial advantages. In many respects theear? rangement is believed to be superior ,to thebestdevice of the priorart. Thus; forexample, 1150 mentionlb'ut a'few of the advantages :of thepres.- ent'invention, automatic braking is unfailingly initiatedinstantly the driver of the vehicle becomes incapacitated, eventhough-he slump over the steering wheel; the structure involves butlittle change in or addition to. vehicles, already made andinoperationsince all the control parts,

are self-contained in theirhousing and since the operating parts aremainly those alreadypresentv on the vehiclagthe sole major changebeingthe, division and s'plining of the steering column. The device isreadily removed: bysimply remov; ing the housing -26 and fastening, thedivided. parts of the steering column together. The-syse. tem involves.no change in operating technique on the part of the .driverexcept thatit requireshim. to maintain .thesteering wheel held up, a'ri-d itv isfoolproof and cannot. be circumvented by the driver.. 7 r

What isclaimed isz a y 1. Abrake applying system .for anautornotivevehicle provided witha-steering column the axis oi which ha averticals-component, said system comprising controlmeans includingiupper andlower steering column parts interlocked for v{rotationtogether and axially slidable .f or lengthwise separation andaswitchadaptedto be operated. to apply a brake whenthe upper part ofthe. steering column is movedrdownwardly;

a 2. A brake applyingsystem foran automotive vehicle comprisingelectrical means for applying a brake, a switch adapted to beclosed toenergize the electrical means, and-a; steering columnthe;

axis of which has a vertical component and which; includes upper andlowerportionsinterlocked forrotation together and axially slidable :forlength-, wise separation. said portions-respectively mounting parts ofsaid :switchf so as to -maintain: the switch open when said portions areextendedand toclose the switch when said portionsv are moved:togetherpfl' i, L J

3. 1A: brake applying system for :ana'utomotive vehicle comprisingelectrical means .fo'rxapplying a brake, a:switch adapted to be closedtoenergize'the electrical means, said'switch being biased toward closingposition and requiring conscious effortby the driver of .the vehicle tomaintain the switch -in open-position and means automatically operativeto openthe switch after the same has been closed for a predeterminedperiod.

"4;- A brake applying' system for an automotivevehicle"comprisingele'ctrical means for applying a brake, a switchmovable .between-terminalopen positions and throughan-intermediateclos'ed pos'itionto control the electricalmeans, saidswitch being' bias'e'd toward one of said terminal'positionsfiand meansfor retarding movement of the switch 'through saidintermediate position.

"5; Abrake applying" system for an automotive vehiclec'omprisingelectrical means -for applying a'brakeya switch movable between terminalopen positions and throughan intermediate closed position toc'ontrol'the electrical" means, said switch being" biased toward oneoisaid terminal positionsi'and a second'switchcontrolling the motivepower of the-vehicle andcooperating with the first switch to deprive thevehicle of motive power whenthe first switch "is in intermediateposition.

"fifiA-brake applyingsystem for an automotive vehicle having an internalcombustion engine and an-ig'nitioncircuitand having a brake,said systemincluding' electrical means-for applying the brake; a switch-movablebetween terminal open positions and=througli1anintermediate closedposition to control the electrical means, said switch being biasedtoward"one of said terminal posi-' tions," and a" switclnin't'heignition circuit 00-- operating withthefirst switch and movable tomediate position. V e g r ;7. Kbrake applying system for-an automotivevehicle'comprising electrical means for applying a brake-amen adapted tobe closed to energize the electrical means, said switch being-biasedtoward closing position and requiring'conscious effort by thedriver, ofthe vehicle to maintain the s'witch" in open position,' and a dashpotdevice for retardin m vement of the" switch from open to c nan it q g 1"8; A brake applying system for an automotive vehicle comprising"electrical 'means for applying a'braketa switch movable;betweenterminalopen positions and through an intermediate closed Open saidcircuit when"the 'iirst switch is in inter position to control the electricalmeans;said switch being biased toward "one of saidterminal poetic and adashpot device for'fretarding movement-oitlie switch from one'ten'ninalposi-' tion to the intermediateposition and fordelaying movement fromthe intermediate position to the other terminal position. 3 v 91Abrakeapplying system for an automotive vehicle"=comprisingelectricalmeans for applying a brake, a switch movablebetween terminalopenpositions and through an intermediate closedposition to control theelectrical means, said switchjbeing' biased toward one of said terminalpositicns. a dashpot device for retarding movement of "the switchfromone terminal position to the intermediate position and for delayingmovement from the intermediate position to the other terminalposition;anda check valve cooperatingwith the 'da'shpot device for preventing thelatter from offering appreciable resistance to position opposite thattoward which it is biased. -10. A brake applying system for anautomotive vehicle comprising electricalmeans for'applying abrake,'a.switch movable through closed position toenergize theelectrical means, said switch being biased into closed position andrequiring conscious effort" by the driver of the vehicle to maintain theswitch in open position, and said switch including a variable resistanceoperable as the switch moves through closed position progressively toincreas the current supplied to the electrical means so as to produce aprogressively increasing brake applying effect. I

-11.'A brake applying system for an automotive vehicle comprisingelectrical means for applying a brake, a switch controlling saidelectrical means an'd'movable' from a first terminal open positionthrough a closed position and into a second terminal open position, saidswitch being biased into said second terminal open position andrequiring a conscious efiort by the driverof the vehicle to maintain theswitch insaid first terminal open position, and means operable as theswitch moves between terminal positions responsive to the biasing toprogressively increase'the current supplied to the electrical means soas to produce aprogressively increasing brake applying efiect.

12. A brake applying systemfor an automotive positions, and a switch intheignition circuit cooperating with the first switch and movable toopensaid circuit just prior to movement of the first switch from theterminal position opposite the last named one to said intermediateposition.

. 13..A brake applying system for an automotive. vehicle having adriving motor, a steering wheel and a brake,said system including meansmounting the steering wheel for movement in its en-- tirety betweenupper and lower. positions, the wheel being biased toward lowerposition, brake applying mechanism operable when the steering wheelmoves from upper position, and means depriving the motor of its drivingpower when the steering wheel-moves from said upper position.' v

14. A brake applying system for an automotive vehicle having a drivingmotor, a steering wheel and a brake, said system including meansmounting thesteering 'wheel for movement in its entirety between upperand' lower positions, the wheel being biasedtoward lower position, brakeapplying mechanism operable when the steering wheel movesfro'm upperposition, and means opmovement of the switch toward the terminal 76erable'to deprive the motor of its driving power Just prior to movementof the steering wheel into saidlower position.

15. A brake applying system for an automotive vehicle having a drivingmotor, a steering wheel and a brake, said system including meansmounting the steering wheel for movement between upper and lowerterminal positions through an intermediate position and said wheelbeing. biased toward lower terminal position, mechanism for applying thebrake operable when the steering wheel is in intermediate position andreleasable when the steering wheel-is. in either of its terminalpositions, and means operable to clerprive wheel is in intermediateposition.

16. A brake applying system for an automotive vehicle having a drivingmotor, a steering wheel and a brake, said system including meansmounting the steering wheel for movement between upper and lowerterminal positions through an intermediate position and said wheel beingbiased toward lower terminal position, mechanism for applying the brakeoperable when the steering wheel is in intermediate position andreleasable when the steering wheel is moved to either of its terminalpositions, and means operable to deprive the motor of its driving powerjust prior to movement of the steering wheel to intermediate positionfrom its upper terminal position.

GLENN KEITH.

ALBERT H. KIRCHNER.

